After update to latest beta, backups broken

So, what is a version I should migrate to? I am running a mix of beta and even older beta on family member systems, but reliability is poor. One family member accidentally upgraded to macOS Catalina.

I probably need to install a new Canary release, and frankly, using that for backups makes my neck hairs stand up. But if I bite that bullet, which one should I use and is upgrading from older betas a smooth ride?